Preparation Of Bismuth Oxybromide Based Photocatalyst And Its Photocatalytic Performance

In recent years,with the rapid development of textile and pharmaceutical industry,a large amount of wastewater is discharged into the environment,which seriously affects the ecological balance and human health.Bi OBr is considered as one of the most promising photocatalytic materials.However,for single-component Bi OBr,its photocatalytic activity is still limited by low visible light utilization rate and high charge carrier recombination rate,which limits its further application.Therefore,in this paper,two Bi OBr based composite photocatalysts were designed and prepared,and showed high degradation characteristics of ibuprofen and azo dyes.The specific research contents are as follows:(1)The surface plasmon resonance(SPR)effect of noble nanometals can be utilized to effectively improve the catalytic performance of semiconductor photocatalysts.In this work,a novel composite photocatalyst of Bi OBr microspheres simultaneously decorated by Ag and Bi dual nanoparticles(NPs)has been successfully synthesized by the hydrothermal method plus one-step reduction method.And the morphology,structure,chemical composition and photoelectrical properties of this composite photocatalyst(Ag/Bi-Bi OBr)were further characterized.Due to the SPR effect of Ag and Bi dual NPs,Ag/Bi-Bi OBr showed the high light absorption with narrow band gap,as well as fast charge separation via metal-semiconductor heterojunction so as to realize an efficient degradation of ibuprofen(IBP)under simulated solar irradiation.Through the further optimization of the loading amounts of Ag and Bi dual NPs,the excellent photocatalytic activity in the Ag/Bi-Bi OBr has been achieved that 92.3% of IBP was removed within 60 min,which is among the best results reported so far for IBP degradation via photocatalysis.(2)A novel composite photocatalyst of Bi nanospheres-decorated oxygen-vacancy Bi OBr hollow microspheres with exposed(110)facets has been successfully synthesized via the hydrothermal method.And the morphological,structural,chemical and photoelectrical properties of this composite photocatalyst(Bi-Bi OBr(OVs))were further characterized.The surface plasmon resonance(SPR)effect of Bi nanospheres,oxygen vacancies(OVs)with exposed(110)facets of Bi OBr hollow microspheres,and the constructed Bi-Bi OBr heterojunction have been synergistically utilized to enhance the photocatalytic performance for degradation of azo dyes.Benefitted from high light absorption,low recombination rate of charge carriers,and abundant catalytic-activity sites in Bi-Bi OBr(OVs),the efficient removal for both methyl orange(MO)and methyl red(MR)has been achieved under simulated irradiation,in which the degradation efficiency of above azo dyes can be up to nearly 100%within 40 min and 90 min,respectively.Most notably,this designed Bi-Bi OBr(OVs)shows the superior capacity with highly competitive advantage on MO degradation via photocatalysis,which is among the best results reported so far.